depends when you passed your test, I passed back in 1991 and can drive upto a 7.5ton on that licence, but things have changed, so you might want to see what it actually says you can drive on the licence (picture licences says at the bottom or back (letter codes).

Rang up the dvla as this has got to be the most simplest way to find out (dont know why i didnt just do that in the first place) and queried the car bit and he said ye that car cans are all the same as long as it does not exceed 3.5 ton